Effects of the Linear Fragments of Beta-(1→3)-Glucans on Cytokine
Production in vitro

1Mechnikov Research Institute for Vaccines and Sera, 105064
Moscow, Russia

* To whom correspondence should be addressed.

Received January 15, 2018; Revision received May 24, 2018
Beta-glucans, homopolysaccharides composed of 3,6-branching
β-(1→3)-D-glucan chains, attract great interest as inducers
of cytokine synthesis. In this work, we studied the ability of linear
fragments of beta-glucan chains to activate cytokine synthesis.
Synthetic nona-β-(1→3)-D-glucoside (SO) representing a linear
fragment of beta-glucan chain, endotoxin (ED), and natural
β-(1→3)-D-glucan (GL) were tested for their role as inducers
of cytokines in whole peripheral blood cultures collected from 17
individuals. The concentrations of IL-12p70, IFN-γ, IL-2, IL-10,
IL-8, IL-6, IL-4, IL-5, IL-1β, TNF-α, and TNF-β were
measured in the supernatants after 2, 24, and 48 h of cell culturing.
SO, ED, and GL stimulated production of pro-inflammatory IFN-γ,
IL-1β, IL-2, IL-6, IL-8, TNF-α and anti-inflammatory IL-10.
The highest levels of biosynthesis after stimulation with SO were
registered for IL-6, IL-8, and TNF-α. SO stimulated production of
all cytokines (except IFN-γ) to a lesser extent than ED and GL.
The IFN-γ/IL-10 (Th1/Th2) ratios after 24 and 48 h of culturing
were 3.1 and 7.5 for SO; 0.03 and 0.1 for GL; and 0.06 and 0.2 for ED,
respectively. The results indicate that linear fragments of
beta-glucans cause a more pronounced shift of immune response towards
the pro-inflammatory (Th1) type than beta-glucan itself.
KEY WORDS: cytokines, inducers, beta-glucans, linear fragments of
beta-glucans, synthetic oligoglucosides